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ANCIENT DOGS                                   423

skeletons of both being in situ ; this animal was about the size of
a Shepherd Dog. The actual Dog of to-day is divisible into more
than 180 different breeds ; but in a work upon " Natural History "
it would seem out of place to enumerate and characterise these
artificial products. Authors vary in their opinion as to what
stock gave rise to the domestic races of the past and of to-day.
The Jackal, the Bunasu (O. primaevus), the Indian Wolf (<7.
pallipes), have been proposed as likely ancestors. It is more
probable that there is much admixture, and that various wild
types have been selected by man in various countries.
Extinct Canidae.óMany of the existing species of Canidae
are also to be found in Pleistocene deposits of the countries which
they now inhabit. A few show a wider range in the immediate
past than in the present. Thus JLycaon (L. anglicus) has been
met with in eaves in Glamorganshire, while Icticyon of South
America appears to be congeneric with Speothos of the Brazilian
caves. The African Otocyon seems to occur in deposits in India.
There are also numerous extinct species belonging to the genus
Oanis, which extend as far back as the Pliocene.
The earlier types of Dogs have been placed in different genera.
Cynodwtis is an Eocene form from European strata. The skull is
decidedly Civet-like, with a short snout. The fore- and hind-feet
were five-toed, with well-developed pollex and hallux. The
dentition was that of modern Dogs, the molars being two in the
upper and three in the lower jaw. The general aspect of the
creature and the form of the skeleton was much like that of the
"Viverrine genus Paradoxurus, of which, as weE as of the Dogs,
Cynodiotis might have been an ancestor.
Simocyon of the Upper Miocene serves as the type of a separate
sub-family of Dogs, Simocyoninae. The skull is short, broad, and
high; the shortening of the skull affecting the jaws has reduced
the teeth greatly; the first three premolars are very small, fall
out soon, and are thus often deficient. There are only two,
molars in each jaw. This type is of course nowhere near the
ancestral Dog. It is a much-specialised branch of an early type.
Cephcdogale is less specialised; there are the usual four pre-
molars. JZnhydrocyon is an intermediate form; it has lost one
premolar in each jaw.
AmpJiicyon, forming the type of another sub-family, Amphi-
cyoninae, though usually placed among the Dogs, presents us with